1. Technical Field
The present invention relates to an electron emission display device and, more particularly, to an electron emission display device which prevents a waveform distortion phenomenon and an occurrence of arcing of an output voltage, and which enables the application of a high voltage to an anode electrode.
2. Related Art
Generally, an electron emission display device is a flat display device that displays predetermined images using light generated by electrons emitted from a first substrate, which electrons collide with a fluorescent layer formed on a second substrate. The first substrate can be a hot cathode electrode or a cold cathode electrode as an electron source.
A field emission display (FED) device is an electron emission display device that uses a cold cathode electrode, and it can be a field emitter array (FEA) type, a metal-insulator-metal (MIM) type, a metal-insulator-semiconductor (MIS) type, or a surface conduction electron-emitting (SCE) type.
The FED device includes a rear panel on which a field emission device is formed, a front panel on which there is formed a fluorescent layer that generates an image using light generated by electrons emitted from the field emission device, and a sealing member that seals the front panel and the rear panel. In this case, the sealing member, an anode electrode disposed on the sealing member, and a cathode electrode-gate electrode disposed under the sealing member constitute a capacitor, and accordingly, the following formula holds:Q=C·V  [Formula 1]
where V is an electric potential difference applied to the electrodes dispose on and under the sealing member, Q is an amount of charge accumulated in each of the electrodes disposed on and under the sealing member when the electric potential difference V is applied thereto, and C is the capacitance, i.e., a constant determined by the geometrical structure of the electrodes disposed on and under the sealing member.
According to the above formula, charges are accumulated on upper and lower parts of the sealing member when voltages are applied to the electrodes disposed on and under the sealing member. In this case, there is a problem in that a desired electric potential difference cannot be applied to the field emission device until sufficient charges are accumulated on the upper and lower parts of the sealing member. Also, there is a problem in that a voltage higher than a certain value is applied to the upper and lower parts of the sealing member until a sufficient amount of accumulated charges are discharged from the upper and lower parts of the sealing member when the voltage applied to the electrodes disposed on and under the sealing member is cut off. These denote a waveform distortion of an output voltage, which eventually may result in the distortion of displayed images. Also, according to the above formula, when the higher electric potential differences are applied to the electrodes disposed on and under the sealing member, the amount of charges accumulated on the upper and lower parts of the sealing member increases. This can cause an arcing of the output voltage, thereby reducing the lifetime of the FED device.